Titre :
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Phylogenetic relationships of filamentous sulfur bacteria (Thiothrix spp. and Eikelboom type 021N bacteria) isolated from wastewater-treatment plantsand description of Thiothrix eikelboomii sp. nov., Thiothrix unzii sp. nov., Thiothrix fructosivorans sp. nov. and Thiothrix defluvii sp. nov.
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Auteurs :
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R. Howarth ;
R. Unz ;
E. Seviour ;
AL Et
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Type de document :
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article/chapitre/communication
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Année de publication :
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1999
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Format :
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p. 1817-1827
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Langues:
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= Anglais
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Catégories :
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MICROBIOLOGIE
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Mots-clés:
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BACTERIE FILAMENTEUSE
;
CARACTERISATION
;
GENETIQUE
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Résumé :
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The relationship of mixotrophic and autotrophic Thiothrix species to morphologically similar chemoorganotrophic bacteria (e.g. Leucothrix species, Eikelboom type 021N bacteria) has been a matter of debate for some years. These bacteria have alternatively been grouped together on the basis of shared morphological features or separated on the basis of their nutrition. Many of these bacteria are difficult to maintain in axenic culture and, until recently, few isolates were available to allow comprehensive phenotypic and genotypic characterization. Several isolates of Thiothrix spp. and Eikelboom type 021N strains were characterized by comparative 16S rRNA sequence analysis. This revealed that the Thiothrix spp. and Eikelboom type 021N isolates formed a monophyletic group. Furthermore, isolates of Eikelboom type 021N bacteria isolated independently from different continents were phylogenetically closely related. The 165 rRNA sequence-based phylogeny was congruent with the morphological similarities between Thiothrix and Eikelboom type 021N. However, one isolate examined in this study (Ben47) shared many morphological features with the Thiothrix spp. and Eikelboom type 021N isolates, but was not closely related to them phylogenetically. Consequently, morphology alone cannot be used to assign bacteria to the Thiothrix type 021N group.
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Source :
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International journal of systematic bacteriology, vol.49, n°4
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